Transcription of Chapter 15 Mixed Models - Carnegie Mellon University
{{id}} {{{paragraph}}}
Chapter 15 Mixed ModelsA flexible approach to correlated OverviewCorrelated data arise frequently in statistical analyses. This may be due to group-ing of subjects, , students within classrooms, or to repeated measurements oneach subject over time or space, or to multiple related outcome measures at onepoint in time. Mixed model analysis provides a general, flexible approach in thesesituations, because it allows a wide variety of correlation patterns (or variance-covariance structures) to be explicitly mentioned in Chapter 14, multiple measurements per subject generally resultin the correlated errors that are explicitly forbidden by the assumptions of standard(between-subjects) AN(C)OVA and regression Models . While repeated measuresanalysis of the type found in SPSS, which I will call classical repeated measuresanalysis , can model general (multivariate approach) or spherical (univariate ap-proach) variance-covariance structures, they are not suited for other explicit struc-tures.
jects. Then the user must specify which of the xed e ect coe cients are su cient without a corresponding random e ect as opposed to those xed coe cients which only represent an average around which individual units vary randomly. In ad-dition, correlations among measurements that are not fully accounted for by the
Domain:
Source:
Link to this page:
Please notify us if you found a problem with this document:
{{id}} {{{paragraph}}}